EP0096963A2 - Ladenachweissystem - Google Patents

Ladenachweissystem Download PDF

Info

Publication number
EP0096963A2
EP0096963A2 EP19830302623 EP83302623A EP0096963A2 EP 0096963 A2 EP0096963 A2 EP 0096963A2 EP 19830302623 EP19830302623 EP 19830302623 EP 83302623 A EP83302623 A EP 83302623A EP 0096963 A2 EP0096963 A2 EP 0096963A2
Authority
EP
European Patent Office
Prior art keywords
fluid
orifice
flow
valve
port
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP19830302623
Other languages
English (en)
French (fr)
Other versions
EP0096963B1 (de
EP0096963A3 (en
Inventor
James Kwok-Fun Yip
William John Novacek
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eaton Corp
Original Assignee
Eaton Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eaton Corp filed Critical Eaton Corp
Publication of EP0096963A2 publication Critical patent/EP0096963A2/de
Publication of EP0096963A3 publication Critical patent/EP0096963A3/en
Application granted granted Critical
Publication of EP0096963B1 publication Critical patent/EP0096963B1/de
Expired legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
    • B62D5/09—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle characterised by means for actuating valves
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/87169—Supply and exhaust
    • Y10T137/87177—With bypass
    • Y10T137/87185—Controlled by supply or exhaust valve

Definitions

  • the present invention relates to fluid controllers, and more particularly, to such controllers which are used in load sensing hydraulic systems.
  • the present invention may be used advantageously with any type of fluid controller which is operable to control the flow of fluid from a source of pressurized fluid to a fluid operated device, wherein the source of fluid includes pressure responsive means for varying the delivery of fluid to the controller.
  • the present invention is especially useful when applied to controllers such as the steering control unit of a full fluid-linked vehicle steering system, and the invention will be described in connection therewith.
  • load sensing controllers has become increasingly popular, partly because such controllers result in a constant fluid flow for a given rate of steering wheel rotation, regardless of steering load, and partly because such controllers save a substantial amount of energy, when compared to conventional open center and closed center controllers.
  • Load sensing controllers are normally used in a system of the type shown in U.S. Pat. No. 3,455,210, assigned to the assignee of the present invention.
  • Such systems include a load sensing priority flow control valve which directs pump output flow to either the load sensing controller, which is the priority device, or an auxiliary load circuit, in response to variations in the steering load signal.
  • the load signal used in such systems was a "static" load signal, i.e., there was no flow in the load signal circuit in the steady-state condition.
  • the load sensing systems initially commercialized used fixed displacement pumps, and because of the constant flow available from the fixed pump, the response time by the system to changes in the static load signal was generally satisfactory.
  • load sensing controllers are being used commercially in systems including load sensing pumps, i.e., the load signal from the controller is transmitted both to the load sensing priority flow control valve and to the load sensing pump. Because the load sensing.pump delivers fluid only in response to a demand for fluid, and must increase pump stroke in order to do so, it has been found that system response time is not always satisfactory when using a static load signal, which is typically bled to the system reservoir when the controller is in neutral.
  • dynamic load signals i.e., load signals wherein a small amount of fluid is pumped from the priority outlet port of the priority flow control valve, through the load signal circuit, and into the fluid controller where it recombines with the main flow path, downstream of the main variable flow control orifice.
  • the use of a dynamic load signal has other advantages besides response time. For example, the dynamic signal, flowing toward the controller, permits the use of a check valve in the load signal line which prevents "wheel kick" by preventing the escape of fluid from the controller when steering against a volume of fluid which is trapped in the steering cylinder.
  • the above and other objects of the present invention are accomplished by the provision of an improved controller for use in the type of system described previously.
  • the controller is of the type including housing means including an inlet port for connection to the source of fluid, a return port for connection to a reservoir, first and second control fluid ports for connection to the steering cylinder, and a load signal port for connection to the priority flow control valve.
  • Valve means is disposed in the controller housing and defines a neutral position and at least one operating position.
  • the controller includes means for imparting follow-up movement to return the valve means to the neutral position in response to the flow of fluid to or from the steering cylinder.
  • the valve means defines a load signal circuit operable to communicate to the load signal port a fluid pressure representative of the steering load.
  • the valve means cooperates with the housing means to define a first flow path communicating between the inlet port and the follow-up means, a second flow path communicating between the follow-up means and one of the control ports, and a third flow path communicating between the other control port and the return port.
  • the first, second, and third flow paths include first, second, and third variable orifices, respectively. At least the first and third variable orifices have a zero flow area when the valve means is in neutral, and a gradually increasing flow area as the valve means is moved toward the operating position.
  • the valve means and the housing means define a drain flow path communicating between the load signal circuit and the return port and including a variable drain orifice having a maximum flow area when the valve means is in neutral, and progressively decreasing to a zero flow area as the valve means moves toward the operating position.
  • the source of pressurized fluid includes means operable to communicate a dynamic load signal into the load signal circuit.
  • the improved controller is characterized by the third variable orifice beginning to open before the first variable orifice begins to open as the valve means moves from the neutral position to the operating position.
  • the variable drain orifice remains open at least until the third variable orifice begins to open, thereby substantially reducing pressure spikes in the flow paths as the valve means moves from neutral to the operating position.
  • FIG. 1 is a schematic of a vehicle hydrostatic steering system including a fluid controller made in accordance with the teachings of the present invention.
  • the system includes a fluid pump 11, shown herein as including a load sensing displacement control mechanism 13.
  • the system also includes a pilot operated, load sensing priority flow control valve generally designated 15.
  • the control valve 15 apportions the flow of fluid from the pump 11 between (1) a primary circuit including a fluid controller, generally designated 17, and a fluid operated steering cylinder 19 and (2) a load sensing auxiliary circuit, generally designated 21.
  • the fluid controller 17 includes an inlet port 23, a return port 25, and a pair of control (cylinder) ports 27 and 29 which are connected to the opposite ends of the fluid motor 19.
  • the controller 17 further includes a load signal port 31, which is connected to a load signal line 33, the line 33 also being connected to a signal port 35 of the priority valve 15.
  • a signal line 37 has one end connected to the signal line 33, and its other end connected to one inlet of a shuttle valve 39.
  • the other inlet of the shuttle valve 39 is connected to a load signal line 41 of the auxiliary load circuit 21.
  • the outlet of the shuttle valve 39 is connected by a signal line 43 to the displacement control mechanism 13 of the pump 11, such that the mechanism 13 is always responsive to the higher of the two load pressure signals present in the signal lines 37 and 41.
  • the priority flow control valve 15 may be of the type illustrated in U.S. Pat. No. 3,455,210, assigned to the assignee of the present invention, and incorporated herein by reference.
  • the priority control valve 15 includes a priority outlet port 45 which is connected to the inlet port 23 of the controller 17, and an excess flow outlet port 47 which is connected to the auxiliary circuit 21.
  • a check valve 48 Disposed in series flow relationship between the priority outlet port 45 and the inlet port 23 is a check valve 48 which is preferably a combination check valve and "pressure drop" valve of the type shown and claimed in U.S. Pat. No. 4,011,721, assigned to the assignee of the present invention and incorporated herein by reference.
  • the check valve 48 is operable to maintain a nearly constant pressure drop, across the valve 48, regardless of the flow rate therethrough.
  • the priority control valve 15 includes a valve spool 49 which is biased by a compression spring 51 toward a position permitting substantially all inlet fluid to flow to the priority outlet port 45.
  • the spring 51 is aided by the pressure in a signal line 53, communicating between the port 35 and the upper end (in FIG. 1) of the spool 49.
  • a pilot signal 55 In opposition to these biasing forces is the pressure exerted by a pilot signal 55, communicated from the priority outlet port 45 to the lower end (in FIG. 1) of the spool 49.
  • the general structure and operation of the priority control valve 15 are well known in the art, and because they form no part of the present invention, will not be described further herein.
  • the priority control valve 15 is of the type which provides a "dynamic" load signal, i.e., one in which there is actual flow through the load signal lines, rather than providing merely a “static” load signal, i.e., one in which there is no flow through the signal lines except during transient conditions.
  • a dynamic load signal i.e., one in which there is actual flow through the load signal lines
  • a static load signal i.e., one in which there is no flow through the signal lines except during transient conditions.
  • the dynamic load signal there is a flow path 57 interconnecting the priority outlet port 45 and the signal line 53, permitting a flow into the signal line 53.
  • the dynamic signal flow is limited by a fixed orifice 59 in the flow path 57.
  • the signal lines 53 and 55 include damping orifices 63 and 65, respectively, to dampen the variations in the opposing pressure signals acting on the spool 49.
  • the fluid controller 17 which is shown in greater detail in FIGS. 2 and 3, may be of the type illustrated and described in U.S. Pat. No. Re.25,126, assigned to the assignee of the present invention, and incorporated herein by reference.
  • the fluid controller 17 defines a fluid flow path communicating between the inlet port 23 and the control port 27.
  • This fluid flow path goes through a fluid meter 67 and includes a main variable flow control orifice 71, and a variable orifice 72 communicating with the inlet of the fluid meter 67.
  • Fluid is communicated from the outlet (metered) of the fluid meter 67 through a variable orifice 73 and a variable orifice 74 to the control port 27.
  • Fluid displaced by the cylinder 19 returns through the control port 29, and flows through a variable orifice 75 to the return port 25, and then to a fluid reservoir 77.
  • the load signal port 31 Also connected to the return port 25 is the load signal port 31, through a variable drain orifice 76.
  • the controller 17 comprises several sections including a valve housing 79, a port plate 81, the fluid meter 67, and an end cap 83. These sections are held together in tight sealing engagement by means of a plurality of bolts 85, which are in threaded engagement with the valve housing 79.
  • the housing 79 defines the inlet port 23, the return port 25, and the control ports 27 and 29 (not shown in FIG. 2).
  • the valve housing 79 defines a cylindrical valve bore 87, an annular groove 89 communicating with the inlet port 23, an annular groove 91 communicating with the return port 25, and a pair of annular grooves 93 and 94 communicating with the control ports 27 and 29, respectively.
  • the controller valving comprising a primary, rotatable valve member (spool) 95, and a cooperating, relatively rotatable follow-up valve member (sleeve) 97.
  • spool rotatable valve member
  • sleeves cooperating, relatively rotatable follow-up valve member
  • spool 97 At the forward end of the spool 97 is a portion having a reduced diameter, and defining a set of internal splines 99 which provide for a direct mechanical connection with a steering wheel W.
  • the spool 95 and sleeve 97 will be described in greater detail subsequently.
  • the fluid meter 67 may be of any suitable construction, but in the subject embodiment, it comprises a gerotor gear set including an internally toothed stator 101, and an externally toothed rotor 103.
  • the rotor 103 defines a set of internal splines 105, and in splined engagement therewith is a set of external splines 107 formed on the rearward end a drive shaft 109, the shaft 109 having a bifurcated forward end permitting a driving connection with the sleeve 97 by means of a pin 111.
  • pressurized fluid flowing through the valving in response to turning of the spool 95 flows to the fluid meter 67, causing orbital and rotational movement of the rotor 103 within the stator 101.
  • Such movement of the rotor 103 causes follow-up movement of the sleeve 97 by means of the drive shaft 109 and pin 111, to maintain an appropriate relative displacement between the spool 95 and sleeve 97, corresponding to a particular rate of rotation of the steering wheel W.
  • the gerotor star brings the sleeve to valve deflection blocking flow to or from the cylinder.
  • a plurality of leaf springs 113 extending through openings in the spool 95 and sleeve 97, urges the sleeve toward the neutral position relative to the spool.
  • the valve housing 79 defines a plurality of axially extending bores 115, each of which communicates through an opening in the port plate 81 with one of the expanding or contracting volume chambers defined by the toothed interaction of the stator 101 and rotor 103.
  • Communicating between each of the axial bores 115 and the valve bore 87 is a meter passage 117 which functions in association with the valving in a manner to be described subsequently.
  • FIG. 3 there is shown in some detail the interface of the spool 95 and sleeve 97, at which valve action occurs.
  • elements of the sleeve 97 are shown by solid lines, and elements of the spool 95 are shown by dotted lines, except where visible through an opening in the sleeve 97.
  • the valve spool 95 includes a circumferential groove 119, and a plurality of slots 121, extending axially to the right in FIG. 3, and communicating with the groove 119. Also communicating with the groove 119 is a plurality of slots 123, extending axially to the left in FIG. 3.
  • the valve spool 95 also defines a plurality of pairs of axial slots 125, and a plurality of individual axial slots 127. Disposed adjacent each of the slots 121 is a drain opening 129, the function of which will be described subsequently.
  • the valve sleeve 97 defines at least one drain port 131, and a plurality of supply ports 133 which are in continuous communication with the inlet port 23. Disposed to the left of the supply ports 133 is a plurality of meter ports 135 which are connected, alternately, to the expanding volume chambers and the contracting volume chambers of the fluid meter 67, by means of commutator action with the meter passages 117, as is well known in the art.
  • the valve sleeve 97 also defines a plurality of cylinder ports 137 which are in fluid communication with the control port 27, and a plurality of cylinder ports 139 which are in fluid communication with the control port 29.
  • the valve sleeve 97 further defines at least a pair of load ports 141, which are in fluid communication with the load signal port 31. Finally, the sleeve 97 defines a plurality of return ports 143, which are in continuous fluid communication with the return port 25.
  • each of the drain ports 131 is in communication with both the adjacent axial slot 121 and the adjacent drain opening 129, to permit flow from the load sensing circuit, through load sensing ports 141, then through the axial slots 123, groove 119, and slots 121.
  • the flow area defined by the overlap of the port 131 and the slot 121 and opening 129 comprises the variable drain orifice 76 of FIG. 1.
  • variable orifices 71-75 all of which are the opposite of the drain orifice 76, in that the variable orifices 71, 72, and 75 have a zero flow area when the spool and sleeve are in neutral, then begin to open when the spool and sleeve are in the transition from the neutral position to the fully open, operating position.
  • the main flow control orifice 71 is defined by the overlap between the supply ports 133 and the adjacent axial slots 123.
  • variable orifice 72 is defined by the area of overlap of alternate meter ports 135 and the axial slots 123, while the variable orifice 73 is defined by the area of overlap of the remainder of the meter ports 135 and the axial slots 125.
  • variable orifice 74 is defined by the area of overlap of the cylinder ports 137 and the axial slots 125, while the variable orifice 75 is defined by the area of overlap of the cylinder ports 139 and the axial slots 127. It should be noted in FIG. 3 that the axial slots 127 are in relatively unrestricted fluid communication with the return ports 143 over the entire range of relative displacements of the spool 95 and sleeve 97.
  • pressurized fluid entering the inlet port 23 would flow through the supply ports 133, filling the axial slots 123, then flowing through the meter ports 135 and through passages 117 and bores 115 (FIG. 2) to the expanding volume chambers of the fluid meter 67.
  • Metered fluid would flow from the contracting volume chambers of the fluid meter 67, through other of the bores 115 and passages 117, and through the alternate meter ports 135 into every other axial slot 125.
  • Metered fluid in the slots 125 flows through the cylinder ports 137 to the control port 27, and fluid exhausted from the cylinder 19 returns to the control port 29, and then to the cylinder ports 139, and into the axial slots 127.
  • Return fluid in the slots 127 flows through the return ports 143 to the return port 125, and then to the system reservoir 77 as described previously.
  • fluid pressure in the axial slots 123 would be "transmitted” through the load sensing ports 141 to the load signal port 31.
  • fluid is pumped from the priority outlet port 45 through the flow path 57 and orifice 59, then through the damping orifice 63 in the signal line 53 to the signal port 35. From the port 35, fluid is pumped through the signal line 33 to the load signal port 31, and from there through the load sensing ports 141 into the axial slots 123, thus "recombining" with the main flow path.
  • the fluid pressure at any point in the load signal path just described is representative of the instantaneous steering load, in the same manner as in the case of a static load signal.
  • variable drain orifice 76 it has been conventional practice in controller design to have the variable drain orifice 76 closed prior to the opening of either the main variable flow control orifice 71 or the variable orifice 75.
  • main orifice 71 it has been conventional design to have main orifice 71 begin to open before the orifice 75 begins to open, and to have the main orifice 71 open at a somewhat faster rate. See for example U.S. Pat. No. 4,043,419, assigned to the assignee of the present invention.
  • FIGS. 4 and 5 there is illustrated a preferred embodiment of the invention.
  • the cylinder port 139 will begin to communicate with the slot 127, and define the variable orifice 75, before the supply port 133 begins to communicate with the slot 123, to define the main variable orifice 71.
  • the spool and sleeve in the positions shown in FIGS. 3 and 4, it may be seen that there is still fluid communication between the drain port 131 and the drain opening 129, defining the drain orifice 76.
  • This orifice sequencing is illustrated in FIG. 5 in the graph of orifice area vs.
  • valve deflection i.e., relative displacement between the spool 95 and sleeve 97.
  • the drain orifice 76 is open in the neutral position (zero degrees), but instead of closing prior to the opening of orifices 71 and 75, the drain orifice 76 of the present invention does not close completely until after the orifices 71 and 75 have begun to open.
  • the variable orifice 75 begins to open before the main variable orifice 71 begins to open.
  • the orifices 71 and 75 in the embodiment of FIGS. 4 and 5, open at approximately the same rate (the ports 133 and 139 are approximately the same size), such that the flow area of orifice 75 is typically greater than the flow area of orifice 71, in the first few degrees of the opening.
  • FIGS. 6 and 7 there is illustrated an alternative embodiment of the invention, in which the cylinder port 139 of the first embodiment is replaced by an elongated cylinder port 139 1 which is disposed circumferentially in such a position that it begins to communicate with the slot 127 at the same time the supply port 133 begins to communicate with the slot 123. Therefore, as shown in FIG. 7, the variable orifices 75 and 71 begin to open at the same time, but still several degrees prior to the closing of the drain orifice 76, as in the first embodiment. However, in the embodiment of FIGS.
  • variable orifice 75 reaches a certain predetermined flow area before the main variable orifice 71 reaches that same flow area.
  • equations for the various system flows are set up, using the well-known flow equation of the form: wherein K is a well-known constant.
  • the equations for the other system flows are as follows:
  • variable drain orifice While the variable drain orifice is open, but the variable orifices 71 and 75 are closed, the orifices al and Ad are related to the specified maximum transition pressure as follows:
  • equation [7] indicates a minimum area of the variable drain orifice necessary to prevent high transition pressures.
  • variable orifice 75 When the variable orifice 75 begins to open, at which point the drain orifice 76 has closed somewhat, main system flow Q may be expressed as follows by assuming negligible pressure drop through orifices 72, 73, and 74:
  • variable orifice 75 Prior to variable orifice 71 beginning to open, variable orifice 75 must increase at a rate equal to or greater than the rate of decrease of the drain orifice 76 in order to prevent high transition pressures.
  • main system flow Q may be expressed as follows by assuming negligible pressure drop through orifices 72, 73, and 74:
  • equation [11] provides the general relationship from which it is possible to size the various orifices, relative to each other, to accomplish the objectives of the present invention.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Power Steering Mechanism (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Servomotors (AREA)
  • Steering Control In Accordance With Driving Conditions (AREA)
EP19830302623 1982-06-14 1983-05-10 Ladenachweissystem Expired EP0096963B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US06/388,378 US4620416A (en) 1982-06-14 1982-06-14 Load sensing system
US388378 1982-06-14

Publications (3)

Publication Number Publication Date
EP0096963A2 true EP0096963A2 (de) 1983-12-28
EP0096963A3 EP0096963A3 (en) 1985-01-09
EP0096963B1 EP0096963B1 (de) 1987-01-14

Family

ID=23533870

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19830302623 Expired EP0096963B1 (de) 1982-06-14 1983-05-10 Ladenachweissystem

Country Status (5)

Country Link
US (1) US4620416A (de)
EP (1) EP0096963B1 (de)
JP (1) JPS596401A (de)
DE (1) DE3369101D1 (de)
DK (1) DK164693C (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0264613A2 (de) * 1986-10-10 1988-04-27 Eaton Corporation Flüssigkeitssteuerung und gedämpfter Flüssigkeitsweg
DE4410693A1 (de) * 1994-03-28 1995-10-05 Hydraulik Nord Gmbh Hydraulische Lenkeinrichtung mit Lastsignal
CN104159807A (zh) * 2011-12-28 2014-11-19 丹佛斯动力系统有限公司 液压转向设备
US9242668B2 (en) 2011-12-28 2016-01-26 Danfoss Power Solutions Aps Hydraulic steering device
US9902422B2 (en) 2011-12-27 2018-02-27 Danfoss Power Solutions Aps Hydraulic steering device
DE102017117149B3 (de) 2017-07-28 2018-11-22 Hydraulik Nord Fluidtechnik Gmbh & Co. Kg Hydraulische Lenkeinrichtung mit Lastsignal

Families Citing this family (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3507901A1 (de) * 1985-03-06 1986-09-18 Danfoss A/S, Nordborg Steuergeraet fuer hydrostatische lenkeinrichtungen
US4781219A (en) * 1986-10-10 1988-11-01 Eaton Corporation Fluid controller and dampening fluid path
DE3814508A1 (de) * 1988-04-29 1989-11-09 Danfoss As Hydrostatische lenkeinrichtung
US4804016A (en) * 1988-06-09 1989-02-14 Eaton Corporation Fluid controller with improved pressure balancing
US4862690A (en) * 1988-10-06 1989-09-05 Eaton Corporation Steering control unit with both flow amplification and manual steering capability
US4936094A (en) * 1989-01-17 1990-06-26 Eaton Corporation Torque-generating steering device with load-sensing capability
US5016672A (en) * 1990-04-23 1991-05-21 Eaton Corporation Steering controller with integral parallel control
DE4342933C2 (de) * 1993-12-16 1995-10-19 Danfoss As Vorrichtung zum Steuern des einer hydrostatischen Lenkeinheit zuzuführenden Drucks
DE19505592C1 (de) * 1995-02-18 1996-04-18 Hydraulik Nord Gmbh Hydraulische Lenkeinrichtung mit Lastsignal
US5620026A (en) * 1995-03-17 1997-04-15 Eaton Corporation Fluid controller and improved backflow prevention therefor
DE19537241C1 (de) * 1995-10-06 1997-05-28 Danfoss As Ventilanordnung für ein hydraulisches Steuergerät
DE19537242C1 (de) * 1995-10-06 1997-05-28 Danfoss As Prioritätsventil für ein hydraulisches Steuergerät
DE19546282C2 (de) * 1995-12-12 1997-09-25 Danfoss As Hydraulische Lenkeinrichtung und Verfahren zum Lenken eines Fahrzeugs
US5732789A (en) * 1996-06-24 1998-03-31 Eaton Corporation Articulated vehicle steering with bogie feedback
US5819532A (en) 1997-06-06 1998-10-13 Eaton Corporation Dynamic load signal fluid controller with instant on flow amplification
US6491118B1 (en) 2000-11-20 2002-12-10 Deere & Company Hydrostatic system with charge flow monitoring
US6782698B2 (en) 2002-09-26 2004-08-31 Eaton Corporation Steering control unit with low null band load sensing boost
DE102006026394A1 (de) * 2005-06-10 2007-02-08 Sauer-Danfoss Aps Fluidregler
US7490626B2 (en) * 2005-10-07 2009-02-17 Eaton Corporation Steer valve with hydraulic vehicle position feedback
US7451686B2 (en) * 2006-08-25 2008-11-18 Deere & Company Fluid system with signal-mimicking device and associated method
EP2610140A1 (de) 2011-12-28 2013-07-03 Sauer-Danfoss ApS Hydraulische Vorrichtung
US9878737B2 (en) * 2015-02-20 2018-01-30 Caterpillar Inc. Hydraulic steering control system
CN104747515B (zh) * 2015-03-18 2017-12-26 北京航空航天大学 基于梭阀调控的智能负载敏感的电动静液作动器
CN104819176B (zh) * 2015-03-18 2017-06-20 北京航空航天大学 基于开关阀和液控单向阀的负载敏感的电动静液作动器
CN104728196B (zh) * 2015-03-18 2017-08-25 北京航空航天大学 负载敏感的电动静液作动器
US10118637B2 (en) 2016-07-08 2018-11-06 Eaton Intelligent Power Limited Load-sensing system
DE102017109798B4 (de) * 2017-05-08 2018-12-27 Danfoss Power Solutions Aps Hydraulische Lenkeinheit
DE102018125053B4 (de) 2018-10-10 2022-02-17 Danfoss Power Solutions Aps Hydraulische Lenkanordnung
CN109058190B (zh) * 2018-10-22 2019-10-29 北京航空航天大学 主动负载敏感电动静液作动器的负载敏感度的控制方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE25126E (en) * 1958-11-25 1962-02-20 Controller for fluid pressure operated devices
US3455210A (en) * 1966-10-26 1969-07-15 Eaton Yale & Towne Adjustable,metered,directional flow control arrangement
US4011721A (en) * 1976-04-14 1977-03-15 Eaton Corporation Fluid control system utilizing pressure drop valve
US4043419A (en) * 1976-06-04 1977-08-23 Eaton Corporation Load sensing power steering system
FR2378195A1 (fr) * 1977-01-24 1978-08-18 Eaton Corp Appareil de commande pour dispositifs actionnes par un fluide sous pression

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3971216A (en) * 1974-06-19 1976-07-27 The Scott & Fetzer Company Load responsive system with synthetic signal
US4017215A (en) * 1976-03-15 1977-04-12 Caterpillar Tractor Co. Infinitely variable orifice for part throttle control
DE2553748C3 (de) * 1975-11-29 1981-05-07 Danfoss A/S, 6430 Nordborg Hydraulische Steuereinrichtung, insbesondere für Fahrzeuglenkungen
JPS52153503A (en) * 1976-06-17 1977-12-20 Toyo Tire & Rubber Co Ltd Pneumatic tire
JPS565989Y2 (de) * 1976-07-23 1981-02-09
US4096883A (en) * 1976-08-24 1978-06-27 Eaton Corporation Closed-center controller and neutral bypass arrangement therefor
US4087968A (en) * 1977-04-28 1978-05-09 Caterpillar Tractor Co. Flow control valve for combining two dissimilar independent systems to a common pressure source
JPS5621602U (de) * 1979-07-27 1981-02-26

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE25126E (en) * 1958-11-25 1962-02-20 Controller for fluid pressure operated devices
US3455210A (en) * 1966-10-26 1969-07-15 Eaton Yale & Towne Adjustable,metered,directional flow control arrangement
US4011721A (en) * 1976-04-14 1977-03-15 Eaton Corporation Fluid control system utilizing pressure drop valve
US4043419A (en) * 1976-06-04 1977-08-23 Eaton Corporation Load sensing power steering system
FR2378195A1 (fr) * 1977-01-24 1978-08-18 Eaton Corp Appareil de commande pour dispositifs actionnes par un fluide sous pression

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0264613A2 (de) * 1986-10-10 1988-04-27 Eaton Corporation Flüssigkeitssteuerung und gedämpfter Flüssigkeitsweg
EP0264613A3 (en) * 1986-10-10 1989-06-14 Eaton Corporation Improved fluid controller and dampening fluid path
DE4410693A1 (de) * 1994-03-28 1995-10-05 Hydraulik Nord Gmbh Hydraulische Lenkeinrichtung mit Lastsignal
US5771692A (en) * 1994-03-28 1998-06-30 Bergmann; Erhard Hydraulic steering unit with load signal
US9902422B2 (en) 2011-12-27 2018-02-27 Danfoss Power Solutions Aps Hydraulic steering device
CN104159807A (zh) * 2011-12-28 2014-11-19 丹佛斯动力系统有限公司 液压转向设备
US9242668B2 (en) 2011-12-28 2016-01-26 Danfoss Power Solutions Aps Hydraulic steering device
CN104159807B (zh) * 2011-12-28 2016-08-17 丹佛斯动力系统有限公司 液压转向设备
US9616919B2 (en) 2011-12-28 2017-04-11 Danfoss Power Solutions Aps Hydraulic steering device
DE102017117149B3 (de) 2017-07-28 2018-11-22 Hydraulik Nord Fluidtechnik Gmbh & Co. Kg Hydraulische Lenkeinrichtung mit Lastsignal
US10960923B2 (en) 2017-07-28 2021-03-30 Danfoss Power Solutions Parchim Gmbh Hydraulic steering facility with load signal

Also Published As

Publication number Publication date
DK164693C (da) 1992-12-28
US4620416A (en) 1986-11-04
EP0096963B1 (de) 1987-01-14
DK164693B (da) 1992-08-03
JPH0448964B2 (de) 1992-08-10
DK270883D0 (da) 1983-06-13
DE3369101D1 (en) 1987-02-19
JPS596401A (ja) 1984-01-13
EP0096963A3 (en) 1985-01-09
DK270883A (da) 1983-12-15

Similar Documents

Publication Publication Date Title
EP0096963B1 (de) Ladenachweissystem
US4759182A (en) Steering control unit with flow amplification
US4336687A (en) Load sensing controller
CA1076417A (en) Horsepower limiter control for a variable displacement pump
EP0187682B1 (de) Belastungsempfindliches Lenkungssystem
US4958493A (en) Open-center steering control unit with flow amplification
US4167893A (en) Load sensing valve
IE43787B1 (en) Vehicle steering system
US5785075A (en) Fluid-flow control valve
US4488569A (en) Apparatus with staged pressure differential for controlling fluid flow
US4781219A (en) Fluid controller and dampening fluid path
US5620026A (en) Fluid controller and improved backflow prevention therefor
US3641879A (en) Central hydraulic system for a vehicle
US4065921A (en) Hydraulic control means, particularly for vehicle steering means
US5101860A (en) Fluid controller and improved check valve arrangement therefor
US4072443A (en) Control valve arrangements for variable stroke pumps
EP0362534A2 (de) Lenkungssteuereinheit mit Strömungsverstärkung und Handsteuermöglichkeit
US3625007A (en) Hydraulic system including flow stabilization means
USRE34746E (en) Open-center steering control unit with flow amplification
US3606755A (en) Power transmission
US5799694A (en) Steering control unit
US4010610A (en) Hydraulic load-sensing system
US4576003A (en) Hybrid load-sense vehicle hydrostatic steering system
EP0689985A1 (de) Servolenkung
EP0107829B1 (de) Hybrides lastempfindliches hydrostatisches Lenksystem für Fahrzeuge

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): DE FR GB IT

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): DE FR GB IT

17P Request for examination filed

Effective date: 19850621

17Q First examination report despatched

Effective date: 19860403

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT

ITF It: translation for a ep patent filed
REF Corresponds to:

Ref document number: 3369101

Country of ref document: DE

Date of ref document: 19870219

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20010404

Year of fee payment: 19

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20010503

Year of fee payment: 19

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20010530

Year of fee payment: 19

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20020510

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20021203

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20020510

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030131

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST